What I want to know is, did that hyena figure it out him/herself on the spot because there was no open wound to work from — hungry enough that necessity became the mother of invention — or is this a commonly known and used entry point?

It’s a commonly used entry point. A couple of years ago my dog had the chance to run around loose in the woods on the edge of a farm and startled a young deer. Dog chased it down, did a kill-bite on it’s neck before we could yank her away. Dog ran back to the kill a few hours later and we found her eating the deer’s anus. Dog is no longer welcome at that farm.

I actually got the assignment to translate and subtitle this doc for a cable channel… The software I work with has no “video off” option so I physically taped a piece of paper across the overlay area on my monitor, leaving only the lower third part visible (where the subtitles go.) Even so, I barely managed to complete the job…

That technique’s good for a lot more than just eating elephants!
By the way, does anyone know if there’s any truth to the recent stories of hyenas wandering into cities & entering people’s bedrooms at night?